(HELP) Feeling attracted for a guy for the first time

(sorry for the TL;DR thing, but I need some help here)I’m a 27 y-o Brazilian guy, living in São Paulo city, and I’ve identified as straight my whole life. I’ve had the same girlfriend since I was 20, but she’s broken up with me in the first week of October. It was very unexpected and harsh and I got really heartbroken after that.My best friend is gay and we share an apartment for a couple of years now. He’s the kind of guy that thinks the best way to go over sadness is to get drunk and dance, so he took me to a gay bar on the day after my girlfriend broke up with me. He got me really wasted before, and I hooked up with this random guy there.Here’s the thing: I’ve never felt attracted to a guy before, and had never experimented anything with guys ‘till now. But I’ve been talking to this guy a lot now and we’ve hang out together a couple of times, and he’s a really nice dude. And I am very attracted to him. We’ve been kissing and making out a lot too lol So you can assume it’s been kinda freaking me out!I still feel very attracted to girls – really, I’ve checked. I’ve looked around at the gym, or work and the streets, and girls still get my attention while guys do nothing for me. I can honestly say when a guy is good looking, of course, but none of them gives me a boner or makes me think like “Huh I’d like to get to know this one”. Only the guy I met at the bar.So I’m freaking out because I still feel bad about my girlfriend and miss her a lot of the time, but I can’t stop myself from feeling sappy when the guy texts me and feel turned on when we are together – and dude has a dick! I’ve never even touched a guy’s dick, but I can feel he has boner when we hug sometimes and it is kind of a turn on booster to me. I don’t want my friend or my ex to know about this. At least not yet, because I don’t even know what it means.I’ve been writing diaries (I do this since I was a kid – I’ll upload them to a blog) to help me think straight (he, pun not intended), but it’s not helping much. So what do you guys say? Am I gay? Am I bi? Wouldn’t I already know for a while if I was able to feel attracted to guys before?I’m not sure what to think anymore x.x